Speaker wire for inefficient speakers?

[PENG]

read about it in 'Good Housekeeping' ...........

Thank you, as always, AH has a good article on this topic.

https://www.audioholics.com/loudspeaker-design/truth-about-matching-amplifier-power

Below is the relevant paragraph, I am quoting it because I happen to agree with him, at least on that part.

You may have heard that too little power will blow a tweeter faster than too much power, and that’s not exactly true. Usually when a loudspeaker is damaged, it’s from too much power for too long a duration, or playing it excessively loud for even a short period. What is true about the “too little power” statement is that when a receiver or amplifier is driven into hard clipping, the resulting distortion has more nasty high frequency content making it easier to damage a tweeter. The term “clipping” comes from the visualization of what the signal looks like on an oscilloscope. The top of the waveform looks flattened, compressed, or “clipped off.” I’ve heard the term used with speakers when they are overdriven to the point where they start to compress transients, either in the drivers or by crossover saturation, but I prefer to use clipping only as an amplifier term. And while I recommend more amplifier power with low-impedance capability, over-driving a speaker is still the fastest way to damage it. Factoring in yet another variable, some amplifiers clip gracefully, either by inherent design or additional circuitry. This is called “soft clipping.” Other amplifier output stages don’t behave as well at clipping, and they produce a cornucopia of odd-order harmonics that can cause tweeter voice coils to overheat.

 

[Mikado463]

Thank you, as always, AH has a good article on this topic.

https://www.audioholics.com/loudspeaker-design/truth-about-matching-amplifier-power

Below is the relevant paragraph, I am quoting it because I happen to agree with him, at least on that part.

You may have heard that too little power will blow a tweeter faster than too much power, and that’s not exactly true. Usually when a loudspeaker is damaged, it’s from too much power for too long a duration, or playing it excessively loud for even a short period. What is true about the “too little power” statement is that when a receiver or amplifier is driven into hard clipping, the resulting distortion has more nasty high frequency content making it easier to damage a tweeter. The term “clipping” comes from the visualization of what the signal looks like on an oscilloscope. The top of the waveform looks flattened, compressed, or “clipped off.” I’ve heard the term used with speakers when they are overdriven to the point where they start to compress transients, either in the drivers or by crossover saturation, but I prefer to use clipping only as an amplifier term. And while I recommend more amplifier power with low-impedance capability, over-driving a speaker is still the fastest way to damage it. Factoring in yet another variable, some amplifiers clip gracefully, either by inherent design or additional circuitry. This is called “soft clipping.” Other amplifier output stages don’t behave as well at clipping, and they produce a cornucopia of odd-order harmonics that can cause tweeter voice coils to overheat.

agreed 100 %, overdriving is bad regardless if done 'cleanly' or not !

 

[TLS Guy]

Those SCM 19 speakers are very good speakers indeed.

ATC is one of the few companies whose specs you can trust.

I had a good long visit to their factory at Stroud in the Cotswolds.

Immense trouble is taken over the design and construction of all their drivers. The voice coils are very carefully wound with flattened wire. The VC is deep in a long gap, and immense care taken to get the absolute smallest of an air gap. This allows really good heat transfer and minimizes dynamic thermal compression. Those are probably the only 6.5" drivers on the planet that really can handle 300 watts cleanly.

The tweeter design is dual suspension and again the VC air gap is so small no ferrofluid is required.

I think ATC make the highest quality moving coil transducers on the planet. I don't think anyone else comes close to the precision of the build of their drivers.

The vast majority of ATC loudspeakers are sold in the professional market. Their speakers are used in the best studios around the world.

The speakers are sealed and have an above average bass response for a speaker of that size. This accounts for the low sensitivity.

I think they would tolerate an amp of 300 watts per channel and would give you another 3 db compared to what you have now.

These speakers are a very easy drive with a minimum impedance of 5.6 ohms at 150 Hz.

You have speakers far and above the quality of what we are usually dealing with on these forums.

 

[John Osborne]

If the response is right that I could get 108 db at 1m then there must be some room left somewhere. While I don't have any meter to measure (it there an "app" for that?), I don't think I am getting anywhere near 100db at 1m.

 

[John Osborne]

and I do not hear any noticeable distortion in the ATC's with the Hegel going full out

 

[TLS Guy]

and I do not hear any noticeable distortion in the ATC's with the Hegel going full out

If that is so, then there are two possibilities.

That Hagel amp is not what it says it is. That is a boutique amp and we have had some red flags raised about amps from that quarter before on these forums.

The more likely possibility though is that the gain structure on your front end is not correct. In other words the components you have connected to the front end does not have sufficient voltage to drive your Hagel amp. So it would mean the output from the units connected to the amp can not drive the amp to anywhere near full power.

What are the sources feeding the Hagel amp?

 

[j_garcia]

If the response is right that I could get 108 db at 1m then there must be some room left somewhere. While I don't have any meter to measure (it there an "app" for that?), I don't think I am getting anywhere near 100db at 1m.

Yep, there sure IS an app for that. Look for SPL meter. A few here have even said one or more of them work decently. I haven't tried the apps because I have a meter.

 

[TLS Guy]

So, that amp failed John Atkinson'd preconditioning test due to overheating. So I would not push that amp hard.

The amp has a voltage gain of 31.6 db. So 150 watts into 8 ohms requires an output voltage 36 volts. So with a standard line or digital input the unit is about 4.5 db short of producing 150 watts into 8 ohms. This is probably deliberate as that with most inputs would limit the amp to being about a 60 watt amp unless you can increase the driving voltage.

I do not believe you could drive those relatively inefficient speakers to 108 db 1 watt 1 meter safely without the amp blowing its cork.

In practice all amps I have ever encountered reach clipping with usual line or digital inputs well before advancing the unit to full volume.

The fact you can turn the volume to full without distress pretty much proves what I'm saying is correct.

Bottom line, I know of no small foot print integrated amp that will do what you are asking.

 

[John Osborne]

The sources are just one. iTunes on an Apple laptop with lossless file digital music through an optical cable.

 

[PENG]

If the response is right that I could get 108 db at 1m then there must be some room left somewhere. While I don't have any meter to measure (it there an "app" for that?), I don't think I am getting anywhere near 100db at 1m.

At 1 m, if the specs are honest, the H160 should be capable of driving one/mono SC19 very close to produce the 108 dB limit, may be missing a dB or 2. That does not include any effects of room gain. The 250 Watts H360 will certainly give you about 2.2 dB of additional headroom. IMO, if the SC19 specs say 108 dB maximum, I wouldn't go near it, to avoid elevated distortion levels.

 

[TLS Guy]

At 1 m, if the specs are honest, the H160 should be capable of driving one/mono SC19 very close to produce the 108 dB limit, may be missing a dB or 2. That does not include any effects of room gain. The 250 Watts H360 will certainly give you about 2.2 dB of additional headroom. IMO, if the SC19 specs say 108 dB maximum, I wouldn't go near it, to avoid elevated distortion levels.

It won't give 250 watts into those speakers. They are truly close to 8 ohms. They dip to 5.6 ohm briefly at 150 Hz.

The gain structure of the Hagel amp is below usual. So actually it will be around 100 db driven from his source. In order to get full output, then the driving voltage needs to be increased above the usual spec. I have no idea what the output from Apple TV can be.

ATC drivers have the lowest distortion in the business even when driven hard. I think Billy Woodman is certainly a candidate for the finest transducer designer of recent times.

 

[yepimonfire]

You are stating the obvious! And I doubt many people forget.. as such. It would be stating the obvious too by saying more load shifted to the subwoofer means less load for the SC19's 6 inch woofers. Regardless, I would still suggest he try a higher crossover to make the sub work harder and that it may help. That particular speaker has quite low sensitivity, the specs claim 85 dB, and according one lab, it could be as low as 83 dB/2.83V.

http://www.avmentor.net/reviews/2016/atc_scm19_2.shtml:

"Average sensitivity (considering measurements in octave steps between 125Hz up to 16kHz) is close to 83dBSPL/2.83V/1m, a performance that undoubtedly classifies the SCM19 as a low-sensitivity loudspeaker"

Again, it is very obvious that there are the demanding midbass/lower midrange that the SC19 still has to produce, but every little bit help when the OP is running out of options. He wants it loud, the speaker has low sensitivity, and is not designed to play very loud. Regarding the 300 W thing, the specs stated: "Recommended amplifier 75 W to 300 W". We don't know exactly what that means. It could mean minimum 75 W and maximum 300 W, implying that the speakers can survive 300 W peaks (that is, not average power) in music contents (that is, not some sine wave test tones) but that would just be my educated guess.

The 75/300 rating sounds like it might have been derived using pink noise with a 6dB crest factor. Klipsch uses a similar method to determine power handling, and this is pretty much standard rating among pro audio systems, by subjecting the speaker to 8hrs continuous pink noise bandlimited to the speakers - 3dB rating. If that is the case, an average spl would be limited based on the 75w rating. A 150w amp would provide a program rating of 150w with 300w of crest factor, much more than that would likely damage the speaker.

An 8' distance would introduce a drop of approximately 7.7dB, limiting op to 103dB average/106dB peak with a 150w amp. That should be plenty loud for music. Not sure what music OP prefers, but some more dynamic music can have crest factors of 12dB, limiting him to around 94dB average. Personally, I rarely listen above 85dB LeqC with music, and I find greater than 90dB begins to become uncomfortable. With movies, I have no difficulty withstanding 105dB or even 110dB peaks, since they are of short duration.

Sent from my LM-X210(G) using Tapatalk

 

[PENG]

It won't give 250 watts into those speakers. They are truly close to 8 ohms. They dip to 5.6 ohm briefly at 150 Hz.

Not sure what you meant. I was simply stating the rated output of the H360, that is 250 W into 8 ohms vs the OP's H160, that is 150 W into 8 ohms. So everything being equal, if he upgrades to the H360, he would gain an additional 2.2 dB (approx.) of head room.

 

[John Osborne]

Many thanks to all. Got a good education. I think what is best for me is to suck it up on those few times I have the house to myself and am in the mood to make the windows rattle (and to answer re what music I listen to in most common order: jazz, blues, reggae, classical, rock). I will just be happy with what I think is terrific sound! Again, thanks.